Clouds Aside, Shuttle Atlantis Set for Wednesday Launch

The shroud-like Rotating Service Structure will be rolled away from NASA's Atlantis space shuttle at Launch Pad 39B on Sept. 5, 2006, allowing a view much like this seen on Aug. 29.Credit: NASA/Jim Grossman.

NASA
shuttle weather officer Kathy Winters said Tuesday that the potential of
cumulus clouds within 10 nautical miles of Atlantis' Pad 39B launch site here
at the Kennedy Space Center (KSC) now give the orbiter a 70 percent chance of
rocketing toward the International
Space Station (ISS) at 12:28:46 p.m. EDT (1628:46 GMT) tomorrow.

Those odds
also include the possibility of isolated showers within 20 nautical miles of a
shuttle runway to be used by Atlantis' STS-115 crew in the case of an emergency
just after launch, Winters added.

"The
discussion lasted five minutes, it was very short," said NASA launch
integration manager LeRoy Cain, who is chairing the preflight Mission
Management Team for Atlantis' STS-115 spaceflight, during a preflight briefing
here.

NASA launch
director Michael Leinbach said sensors in Atlantis' aft picked up minute
amounts of gaseous liquid oxygen, which is used alongside liquid hydrogen to
power the shuttle's fuel cells in orbit. The sensor reading is likely due to a
slight misalignment between a ground system and the orbiter, though the two
systems are now detached, he added.

"This is
not a problem for us," Leinbach said, adding that he does not expect to see the
reading again before launch. "This is not a constraint."

Meanwhile,
launch pad workers are hoping to roll back a shroud-like Rotating Service
Structure - which protects NASA shuttles from poor weather - by 3:00 p.m. EDT (1900 GMT) before afternoon
thunderstorms arrive in the area. The activity could be pushed up an hour at the
most, NASA officials said.

Wayne Hale,
NASA's space shuttle program manager, said that Atlantis' STS-115
astronauts could gain two extra mission days if they launch Wednesday or
Thursday, which could ease a busy schedule that includes two
back-to-back spacewalks this weekend.

If needed,
an extra day could be inserted on Flight Day 5 - which would be Sunday given a
Sept. 6 launch - to allow a focused inspection of Atlantis' heat shield, Hale
said.

While NASA
is now routinely conducting a Flight
Day 2 check of a shuttle's heat shield using a sensor-laden inspection boom
that adds an extra 50-foot (15-meter) reach to the orbiter's robotic arm. But a
focused inspection to take an up-close look at certain areas will only be added
to the STS-115 crew's schedule if absolutely necessary, NASA officials said

"We don't
have that scheduled on the STS-115 timeline but we know that it is a
possibility," Hale said of the focused inspections, adding that a second heat
shield check is also scheduled near the end Atlantis' flight to scan for
orbital debris damage. "There is a hope that, perhaps, we won't need to do
that."